Out of sight, out of mind, goes the old expression. Vehicle owners largely ignore the most complex and expensive component of their car or truck – the transmission. Diligent owners may check the dipstick to ensure there’s adequate transmission fluid occasionally but it’s largely ignored.

The best way to check the health of the fluid is to put the dipstick against a white background such as a paper towel. It should be a red color. The fluid over time will take on a brown color, indicating a change is due.

They’re a number of reasons why transmission problems occur: most prevalent is overheating. Under a heavy load, such as when towing a trailer, racing, rocking the vehicle to free it from snow, stop and start in traffic. Most of the transmission problems starts from overheating. Under heavy load, such as when towing a heavy trailer, rocking the vehicle from the snow, having continuous stop and go traffic in hot weather (think rush hour), racing, etc. the transmission overheats. At elevated temperatures the transmission oxidizes, lubricating qualities diminish leaving deposits inside the transmission. Check the automatic transmission fluid in an overheated transmission, it would be dirty and dark and, with a strong burning smell. Rubber seals, O-rings become brittle and hard. The metal parts warp causing valves to stick.

Changing transmission fluid normally occurs between 40,000 to 96,000 kilometers. Check the owner’s manual for recommendations.